Comparing these cameras is a apples and oranges exercise. I hope this article helps you can make a decision based on fact not marketing hype or biased comment. Note that as a f900 owner I am more familiar with the f900 than the Varicam.

COMPRESSION Ask to see a split screen comparison recording of uncompressed HD and HDCAM from a f900.ie record HDSDI output from camera direct to NLE and at the same time record to tape. Split screen the two.

If a test is not available then simply switch between playback and live camera output on a 24 inch monitor.

Does it look like 2/3rds of the colour information is "thrown away"?

Another test, ask your favorite post house to record a uncompressed image to HDCAM. Do a split screen with the original image. You'll be surprised at the result. Do the same with varicam.

Someone may show you a multiple generation test of how blocky HDCAM can get. Such tests are usually technically correct but ignore "work arounds" in common practice. Who is stupid enough to make multiple generation dubs on HDCAM when SDTI cloning is an option? (The post house that does not want to buy a SDTI card for its HDCAM decks!) Same applies to Varicam where there is an sdti option and now option to playinto FCPHD via firewire.

12Bit v 10Bit In respect of comparing camera heads bear in mind that the panasonic and Sony HDW750 has a 10 bit AtoD and the Sony f900a 12bit. So the f900 theoretically has greater dynamic range, more tones and colours at the camera head.

What is the difference between a 10bit and 12bit head?

The words vibrant and rich has been used to describe the panasonic. When Sony introduced the 700 (10bit) digibeta camcorder, vibrant and rich were also used to describe the picture. But on a large screen vibrant can look plastic when the eye seeks out more tonal variation. The new Sony HDW 750 also has a 10bit head and looks "vibrant" in comparison to the f900 which has amore subtle range of tones in my view.

When viewing HD pictures for analysis avoid Plasma displays which only work at 8 or 10bit. They do not display subtle tones. A shot taken with a 10bit camera, of a tropical beach, with blue sky, bright green foliage and emerald sea looks like a postcard on a plasma screen.

Will your viewers notice the difference?

CINEGAMMA Both cameras have cine gamma curves which exaggerate the knee and is meant to help film dps who have difficulty lighting for ccds :)

However, it does not alter the fact that the imager is a ccd and needs a different lighting approach to lighting film. Cinegamma curves divide the pie differently, they do not make the size of the pie any bigger. CCDs have a fixed dynamic range, altering the gamma curve redistributes the camera processsing so minor gains are made in processing of the highlights.

TIMELAPSE In respect to ramping neither cameras are capable of *recording* under 23.97 frames per second. The varicam cannot *record* less than 59.97 frames per second.

With the Varicam you can decide on location the precise frame rate you need from 1 to 60. With f900 all 24 frames are recorded per second, delaying the decision to post. This takes control away from the DP.

You can use a portion of the shot in real time should something interesting happen. The varicam will exhaust a 30 minute tape in 30 minutes of location recording even thought you may only be committing one frame per second to tape. (A shooting ratio of 60 to 1)

If buying multiple cameras is an option then the cheaper HDW750 has a time lapse option that records 200 frames to RAM then downloads to tape. It replays the timelapse effect straight from the camera. The Varicam replays all 60 frames per second including buffer frames so replay of the timelapse effect on location from the camcorder is not possible.

The Varicam and the HDW750 benefit from less than 1/24th second exposure in time lapse mode which gives the characteristic blur of motion. The f900 cannot do this.

SLO MOTION Both Varicam and HDCAM, up to 60fps require a post process to extract slomotion sequence from the original recording.

At 60p frame rate the Varicam is native and requires no post process. Frame rates up to 60 are possible with HDCAM. Half vertical resolution but full horizontal resolution image is derived from the original HDCAM recording.

So HDCAM at 60 is made up of a 1440x 540 image which is interpolated to 1920x1080, Varicam at 60fps is 960x720 interpolated to 1920x1080. Technically then the HDCAM has more pixels, but in reality the Varicam seems a little sharper at 60p at least on smaller screens, possibly due to our eyes greater sensitivity to vertical resolution than horizontal.

SAMPLING Our film friends describe conversion of 4k to 2k as "super sampling", and state that it is a good thing, yet the same guys describe the process as "compression" when referring to sampling of HD cameras!

Panasonic Varicam has a 1 million pixel imager. Sony has 2.1 million pixel imager (both cameras do not use all of the pixels) Varicam records 960x720 pixels of luminence detail Sony 1440x1080 pixels of lumence. On playback vtrs convert the image up to 1920x1080 pixels. HDCAM samples the original 1920x1080 to 1440x1080 whereas the Varicam samples 1220x720 to 960x720. So comparing the two is a apple and oranges comparison.

The often quoted compression figures of 3:1:1 and 4:2:2 when used as a direct comparison are misleading.

Both manufacturers can be blamed for this.

As the f900 starts out with more pixels, it is fair to say that a HDCAM recording has greater colour and luminance detail of that scene than the Varicam (when both are uprezzed back to 1920x1080) The 4:2:2 recording is easier to pull a key from but the picture is lower resolution.

Sure a key is going to be easier from a low res 4:2:2 image than a higher res 3:1:1 image. But what happens to the picture when it is bumped up to 1920x1080? Colour detail in the original image of the scene is 480 x1080 on HDCAM and 480x720 on Varicam, luminance 1440x1080 on HDCAM and 960x720 on Varicam.

So when both cameras are pointed at a scene the HDCAM records more actual detail in luminence and colour than Varicam.

COST The cheaper Sony 7 series cameras and the Varicam reduces the total cost of a typical drama kit by around 30% compared to f900.